Bacterial contamination of blood products is currently a major problem in transfusion medicine and a leading cause of transfusion-related deaths. Platelets are particularly susceptible to contamination because they are stored at room temperature. [unreadable] [unreadable] BCR Diagnostics, Inc. (BCR) has developed a novel biosensor platform for detecting low levels of bacteria in real time (i.e., about 2 minutes). During Phase I, BCR has demonstrated the feasibility of adapting its technology to developing a low-cost biosensor for detecting bacteria in platelet concentrates shortly before transfusions. BCR's biosensor is based on the LEXSAS (Label-free Exponential Signal-Amplification System), a unique methodology using spores as ultrasensitive nanodetectors capable of emitting fluorescent light signals when encountering single bacterial cells. [unreadable] [unreadable] For Phase II, BCR proposes: 1. To construct a marketable biosensor prototype that will extend the system's sensitivity to single bacterial cells. 2. To use the prototype for a study designed to obtain experimental data that will meet the Food and Drug Administration (FDA) requirements for premarket approval of the biosensor. [unreadable] [unreadable] The study will consist of three major tasks: 1. To test, optimize, and standardize the biosensor prototype in terms of sensitivity, completion time, analysis reproducibility, and dynamic range. 2. To use the prototype for experiments designed to obtain a "Data Package" to be submitted to the FDA. This task includes experiments that will show the accuracy (sensitivity and specificity) of the biosensor for identifying platelet concentrates spiked with a panel of about 13 different bacterial strains from a list provided by the FDA. 3. To do a double-blind study to validate the commercial usefulness of the biosensor. [unreadable] [unreadable] Other potential applications of the bacteriologic biosensor include: diagnostics, environmental surveillance, food and beverage monitoring, and sterility testing. [unreadable] [unreadable]